This series of three-winding oil-immersed power transformers covers rated capacities from 6300 kVA to 63000 kVA, with Class 1 (Type 22), Class 2 (Type 20), and Class 3 (Type 18) energy efficiency grades. Featuring a YNyn0d11 connection group (customizable), 100/100/100% winding capacity distribution, and on-load tap changing capability, they enable continuous voltage regulation under load. Designed for power transmission and distribution systems, they meet IEC and GB standards, offering low losses, high reliability, and customizable voltage combinations for diverse utility and industrial applications.